The protection of agricultural and horticultural crops from diseases is important to ensure stable agricultural production, and various fungicides are used for this purpose. However, fungi become resistant to fungicides over years, and thus novel fungicides that are effective not only to drug-sensitive fungi but also to drug-resistant fungi are demanded.
Regarding 1,3,5,6-substituted-2-pyridone compounds, for example, 1,3,5,6-substituted-2-pyridone compounds having an aryl group or a heteroaryl group at the 3-position are disclosed as GABA alpha 2/3 ligands (see, for example, WO 98/55480). Further, 1,3,5,6-substituted-2-pyridone compounds having a carboxyl group at the 3-position are disclosed as bacterial infection treatment agents (see, for example, EP Patent No. 0308020).